As set forth in the Deckner U.S. Pat. No. 4,563,346, an ideal composition for delivery a topically-active compound to skin or hair should be stable and should deliver the topically-active compound such that it adheres to the skin or hair while topically-inactive ingredients evaporate or are otherwise removed from the area of application. Topically-delivered active compounds, such as cosmetics, like an antiperspirant compound, and topical medications, like an antibacterial or an anti-inflammatory, traditionally have been prepared as either oil-in-water emulsions or water-in-oil emulsions. However, topically-effective compositions prepared as emulsions feel wet or oily when applied to the skin, and often remain sticky after the composition carrier vehicle evaporates. Furthermore, emulsion-type compositions require a relatively long time to dry after topically application. In addition, many emulsion-type compositions leave a white residue on contacted skin or clothing, and actually stain clothing.
Nonemulsified anhydrous compositions, like antiperspirants, are known in the art. For example, non-emulsified, oil-based topically-effective compositions are available, however these products often require shaking prior to each use in order to redisperse the insoluble topically-active compound that has separated from the composition. For example, U.S. Pat. No. 3,873,686 discloses an anhydrous, liquid or cream antiperspirant composition comprising an alcohol-soluble aluminum chlorohydroxide-polyol complex in an anhydrous ethanol vehicle. Similarly, U.S. Pat. No. 4,137,306 discloses the above-described anhydrous antiperspirant composition in solid stick form. U.S. Pat. Nos. 4,053,581; 4,065,564; and 4,073,880 disclose liquid anhydrous antiperspirant compositions useful as pump-spray and roll-on products, wherein the antiperspirant compounds are solubilized in a vehicle including ethanol and a sufficient amount of a volatile or a non-volatile silicone liquid to reduce tackiness of the antiperspirant. U.K. Patent Application No. 2018590A describes an anhydrous antiperspirant spray composition including from 60% to 90% of a volatile cyclic silicone in order to improve composition efficacy by increasing adherence of the antiperspirant composition to the skin and hair. Nevertheless, although suspending agents are included in each of the above-cited references, the antiperspirant compositions require shaking before use in order to redisperse the separated antiperspirant compound.
Stable, nonseparating antiperspirant compositions also are known in the art. U.S. Pat. No. 4,749,569 discloses an extrudable antiperspirant paste, or cream, composition stabilized against phase separation by thickening the antiperspirant composition with from 4.6% to 9.5% of a finely-divided silica and from 2% to 25% of a quaternized three-layer clay exfoliated with a polar solvent. If a finely-divided silica is used as the sole thickening, or suspending, agent, then an unstable product results. Therefore, an additional suspending agent, like an organoclay, is included in the composition. However, the presence of an organoclay in an antiperspirant composition is a principal source of the whitening and staining of the skin and clothing.
Nabial, in U.S. Pat. No. 4,425,328, discloses a stick antiperspirant composition including a volatile silicone; a relatively high amount of a waxy matrix, i.e. from about 17 to 30 percent by weight; and a suspending agent to suspend the antiperspirant compound. Nabial specifically discloses using a clay as a suspending agent for the disclosed solid compositions. In contrast, the present compositions are stable liquid or flowable semisolid products that effectively resist phase separation by including a relatively low amount of a wax, i.e. up to about 4.5% by weight of the composition. Furthermore, an important feature of the present invention is to provide a composition absent a clay suspending agent that stains the skin and clothing.
Davy et al. U.S. Pat. No. 4,126,679 discloses a cosmetic stick composition. The Davy et al. composition includes from about 15% to about 70% of a long chain alcohol having 16 to 22 carbon atoms. The long chain alcohol is a wax, and the relatively high amount of the long chain alcohol suspends the other ingredients in the stick composition. In contrast, the present liquid or flowable semisolid composition includes no more than about 4.5% by weight of a wax, and, surprisingly, exhibits essentially no phase separation after long storage periods.
Bissett et al., in European Patent Application No. 88309740.4, disclose pharmaceutical and cosmetic compositions including tocopherol sorbate for topical application to the skin. The Bissett et al. application is directed to compositions that protect the skin from the harmful effects of sunbathing. Bissett et al. do not teach a stable liquid or cream composition comprising a topically-active compound and a suspending agent including a finely-divided silica and a suspending wax composition, wherein the composition resists phase separation and is nonwhitening and nonstaining to skin and clothing.
Palinczar, in U.S. Pat. No. 4,724,139, discloses an antiperspirant composition including a volatile isoparaffin liquid, a water-insoluble wax and an antiperspirant salt. Palinczar includes a minimum of 5% of the water-insoluble wax in the composition. In contrast, the present composition includes a wax in a maximum amount of about 4.5% by weight, because greater amounts of a wax provide a solid composition. The present composition is a liquid, a flowable semisolid or a nonflowable semisolid, having a viscosity in the range of from about 1000 cps (centipoise) to about 100,000 cps, that effectively resists phase separation by utilizing a low amount of a wax compound in the suspending wax composition.
Shin U.S. Pat. No. 4,937,069 discloses an anhydrous semi-solid antiperspirant composition that includes a minimum of 2% by weight fumed silica; a volatile emollient; a nonvolatile emollient; and a thickener. The composition disclosed by Shin is a cream or gel having a viscosity in the range of 100,000 to 8,800,000 cps (centipoise). The present composition is a liquid or a flowable semisolid including a maximum of less than 2% by weight finely-divided silica and demonstrating a viscosity in the range of from about 1,000 to about 100,000 cps.
Coopersmith U.S. Pat. No. 3,818,105 discloses that C.sub.12 to C.sub.14 isoparaffinic hydrocarbons, when combined with naphthenic materials, are useful in a wide range of cosmetic formulations for lubrication of the skin to achieve a quick spreading, non-greasy application with evaporation of the hydrocarbon after use without a greasy buildup. While the hydrocarbons disclosed in the Coopersmith patent lubricate the skin for better application of the cosmetic formula, the compositions of Coopersmith do not achieve the unexpected stability achieved in accordance with the present invention. Other compositions containing volatile hydrocarbons, such as those disclosed in Bolich U.S. Pat. No. 4,472,375, require polymeric water-soluble thickening agents, such as guar gum, to effectively stabilize the compositions.
Similarly, Spitzer et al., in U.S. Pat. No. 4,174,386, disclose an aerosol antiperspirant composition utilizing a volatile hydrocarbon including about three or four carbon atoms as the propellant. The present composition also can include a volatile hydrocarbon. However, the hydrocarbons used in the present invention include at least 10 carbon atoms and up to about 32 carbon atoms; act as a volatile carrier for the nonvolatile components of the composition; and then evaporate from the skin or hair after topical application of the composition. The stability of the anhydrous compositions of the present invention, achieved with a new and improved suspending agent including a finely-divided silica and a suspending wax composition, is unexpectedly superior to each of the above-identified prior compositions in regard to syneresis, cosmetic feel and degree of skin and clothing staining.